Available from https://utextension.tennessee.edu/publications/documents/pb1640.pdf, Foster, R., and A. Ellis. A companion publication, Circular 671, Designing Solar Water Pumping Systems for Livestock: User Manual (https://pubs.nmsu.edu/_circulars/CR671.pdf), provides step-by-step instructions for using a Microsoft Excel spreadsheet to perform necessary calculations for designing a solar pumping system. A deep setting will increase cost, length, and weight of pipe and cable. <>
For surface sources, a well-vegetated riparian zone establishes a buffer that filters and purifies water as it moves across the zone, reducing sediment loads, supporting soil stability, improving water quality, and enhancing wildlife habitat. Pumps and watering systems for managed beef grazing [Online]. Depending on climate and usage, storage tank capacity should equal 3 to 10 days of water use. Some users are even powering broken windmill pump jacks with portable photovoltaic (PV) systems. <> endobj 2003. The total length of pipe is 150 (well water depth) + 80 (distance from well to storage tank) + 8 (distance from surface discharge to tank) = 238 ft. From the HL calculation (Equation 3), 100 ft of 0.75-in. Codes and standards, including the National Electrical Code (Wiles, 2001). The Array Sizing spreadsheet tab involves the automatic sizing of the PV array given the calculated and manually selected pump parameters. Each module is portable and therefore available for displays and presentations. (Photo from National Renewable Energy Labs, 1997. % In addition, these factors should be considered: Who will install and maintain the system. The flow rate (gpm) is the volume of water that is pumped in a set time period and is determined via Equation 7. OCU#|r2:@9*f`UX s"6|xOSUxsUmM)NHpXVB,@FDgm9Xqy(@ c 2 <> Variable water delivery depending on sun intensity, Higher initial costs (although costs are trending lower), Acceptable capital costs and low recurring costs, Reliable warranty of 20+ years for panels, System is modular and may be modified to fit needs. 2. 8 0 obj Pipe, fittings, and other balance-of-system components (a common mistake is to oversize the piping).
5 0 obj 13Draw-down is the level of water that may drop in the well as pumping occursthe well pipe is refilled at a recharge rate. Other components that should be considered within the system are: A livestock watering well will be used in this example. ), Figure 4. <> PV panels are installed with mounting hardware that allows the panels to be oriented 6 to adjust the tilt of the modules to an optimum angle, elevate the modules for security, and minimize shading and damage (Figure 4). In designing an efficient system, one should minimize the amount of work required of the pump, which minimizes the amount of energy needed to operate the pump and thus the size and cost of components. A multiplier may be added that can provide an extra water cushion, offset evaporation losses, or refill the storage tank. Pumps are classified as either positive-displacement or kinetic/centrifugal, and each has advantages. Once the daily water requirement is calculated, the solar resourceinsolation, or total sunlight reaching a specific locationis determined. Because we round up the number of strings and parallel combinations to whole numbers, the total amount of energy and therefore water pumped will be greater than our daily requirements on any full sunny day. <> This will reflect an approximate cost to construct the system plus the costs of other materials, labor, sales taxes, shipping, etc.
gs@OVd @rQ\ k-%gD endobj For permission to use publications for other purposes, contact pubs@nmsu.edu or the authors listed on the publication. r)4LY6D 18 0 obj Each PV module has an operating output current and voltage. hbbd``b`v@IHp@u B H0,A@bA R"ZAb@BHpG $ RHp \, A 2 2$"@A,s dAEg~` $$ <> He previously worked for many years in both private and public sectors as a computer scientist and engineer. The water level variable in Equation 2 is measured from the water surface to the level of the water in the sourcenot the depth location of the pump. The piping is 0.75-in. Available from https://extension.missouri.edu/p/EQ380. Contents of publications may be freely reproduced for educational purposes. 23 0 obj Renewable energy for water pumping applications in rural villages [Online; NREL/SR-500-30361]. Once the total gallons/day/animal figure is calculated and any extra water requirements are entered, values are summed to yield the total daily water requirement in gallons/day. Voltage multiplied by current determines total power provided by the PV array in watts (or converted to horsepower, HP). Excess power produced by solar panels can be used for cathode protection, to aerate a dugout, or to power an electric fence. WlU endobj Losses due to fittings may be significant. %PDF-1.7 Modules are sized as DC power (watts [W]) and come in all sizes, from a few watts to over 250 W. Rated power is determined by the output voltage and current under standard sun intensity. A good match between the pump, PV array, and system parameters is necessary to achieve efficient operation (Morris et al., 2002). Research also shows that yearling steer performance increased 23% when supplied with an alternate water source rather than dugouts (earthen dams or reservoirs).
Windmills are still a common source of power for off-the-grid water pumping systems. pipe at 4 gpm has a pressure drop of 4.9 ft/100 ft of tube, which yields 4.9 238 / 100 = ~11.74 ft. x+*@02,L-T5300700THMLO5PpW M %PDF-1.5 % Studies have shown that, when given a choice, cattle drank from a water trough 92% of the time rather than from a nearby stream (Bartlett, n.d.).
In many parts of the world, including New Mexico (NM), water and energy availability are growing concerns. Using the spreadsheet allows you to test various design scenarios and demonstrate the design method and terminology for a direct-coupled solar water pumping system. Applied fluid mechanics (6 ed.). 0
OPSdG."l Figure 2. endobj This publication provides a general discussion of how to design a photovoltaic-powered solar water pumping system for livestock. #(4/g&ww6?wI:W9YZt}iVE?3Z.r. This direct-coupled system is intended to operate only during the day when sunlight is present, thus eliminating the expense and complexity of batteries 4. 2007. and how much power (watts) is required to run this pump assuming standard pump efficiency ( ~35%). Because of a variety of benefits, and increased regulations in some states, it is often desirable to move water from a surface source to a different location, elevation, or drinker, or to pump water from a remotely located well. %PDF-1.4
%
2 0 obj By using a simple direct-coupled approach, the operation, maintenance, costs, and complexity of the system are greatly reduced. The description and quantities for specific items are obtained from calculations or specified by you. Thomas Jenkins has been a professor in NMSU's Department of Engineering Technology and Survey Engineering since 1990. endobj Available sunlight, which depends on location. A Microsoft Excel spreadsheet to provide an easy and visual educational tool to present concepts behind PV technology and system design methodology (available to download at https://pubs.nmsu.edu/_circulars/CR671/CR671.xlsm ). Pumps may be submersed in a well as deep as necessary to ensure reliable water supply (taking into account drawn-down levels, seasonal variations, and recharge rates). The storage tank size is calculated by multiplying the days-of-storage requirement by the daily water requirement and is provided as a reference only. Since the process to design and implement such a system may be a challenging task, New Mexico State University's Engineering NM program initiated a project to provide the Cooperative Extension Service (CES) with a demonstration module, an interactive design spreadsheet, and literature related to solar water pumping to better inform NM water users about the benefits and methodology of implementing this technology. Common values of required gallons per day per animal in New Mexico can be found in the Daily Water Requirement spreadsheet tab or in Table 2, but you have the option to change these default values depending on your unique situation 10. Solar energy: Renewable energy and the environment. Water level sensor for on/off operation if using storage. By providing storage, a producer can still provide their daily water requirements from the storage tank at night or on cloudy days. By wading into surface sources, cattle pollute the water with their urine and feces and may disturb the water with their wading action. endobj Pumps move water from wells or surface sources. 82 0 obj <>/Filter/FlateDecode/ID[<7369D0785D694D96A2AE0DA0CA9361B0><13FC2B2A60EEE14D9594F7E2A94E94CA>]/Index[43 71]/Info 42 0 R/Length 155/Prev 110540/Root 44 0 R/Size 114/Type/XRef/W[1 2 1]>>stream
24 0 obj 2 0 obj endstream endobj 44 0 obj <>>> endobj 45 0 obj <>/ExtGState<>/Font<>/ProcSet[/PDF/Text]/Shading<>/XObject<>>>/Rotate 0/TrimBox[0.0 0.0 595.276 841.89]/Type/Page>> endobj 46 0 obj <>stream $.'
Surber, G., K. Williams, and M. Manoukian. Available from https://www.clemson.edu/sustainableag/IP217_solar_livestock_watering.pdf. Placing the pump lower in the well (increasing its submergence) will NOT cause it to work harder or to pump less water, nor will it increase stress or wear on the pump. <> ), nitrogen, phosphorous, suspended solids, and surrounding erosion are realized. endobj 1997. 2002. This is typically not an issue when float switches are incorporated into storage systems, which will stop the pumping when the tank is full. 2006. Solar water pumping systems are composed of two primary components other than the well itself: the PV panels (or modules) and the pump. Boca Raton, FL: Taylor & Francis Group. The abundant and varied benefits of PV systems make them attractive in many situations. or wells accessing underground aquifers1. This section will reference the accompanying Excel spreadsheet covered in Circular 671 (available to download at https://pubs.nmsu.edu/_circulars/CR671/CR671.xlsx). Solar pumping systems for surface sources or wells can be portable, which is appealing because more and more producers want systems that can move among various locations. These friction losses, which are expressed in equivalent lengths of vertical pipe distance, are added to the static head to yield an equivalent TDHi.e., what equivalent height would the pump need to move water given these values. 15 0 obj 4Batteries are expensive, must be replaced every few years, and require periodic maintenance, while the useful life of storage tanks may be decades. NOTE: It is possible that there will only need to be a single module or modules only in series and not in parallel. endobj 6 0 obj 10 0 obj In windy, hot, dry areas, you should also take into account evaporation losses associated with open storage methods. Solar pumps are low volume, pumping an average of 1 to 5 gallons per minute (gpm). Electricity when and where you need it: From the sun: Photovoltaics for farms and ranches [Online; NREL/BR-412-21732]. (Photo from National Renewable Energy Labs, 1997.). <>/Metadata 656 0 R/ViewerPreferences 657 0 R>>
Environmental benefits (including low noise). Livestock, crops, and people often depend upon surface sources of water (streams, ponds, catch tanks, etc.) 3It can cost $10,000 to $30,000 per mile to install electrical power line through rugged terrain. Circular 670 Thomas Jenkins College of Agricultural, Consumer and Environmental Sciences and College of Engineering, New Mexico State University. n.d. Solar-powered livestock watering systems [Online]. 2004. Q is the flow rate in gpm, D is the nominal inside diameter of the pipe in inches, and L is the total length in feet of the pipe for the system. Boyle, G. 2004. To determine Daily Water Requirement using the spreadsheet tool, enter the quantity and type of animals (cow, horse, etc.) Calves require higher-quality water and will not fight cows or mud to obtain it. A good rule of thumb is that the solar resource must be greater than 3.0 kWh/m2 per day (3,000 watt-hours per square meter of area in one day) for choosing a solar 12. The well is 80 ft from the storage tank, and the delivery pipe rises 8 ft to discharge into a tank. New Mexico State University is an equal opportunity/affirmative action employer and educator.
Irrigation water demand depends on local conditions, season, crops, methods of delivery, and evapotranspiration 11. Agriculture watering is usually greater in summer seasons when solar radiation is at its highest.